5x+2y=20
Substitute 0.3 for x
5(0.3)+2y=20
Multiply 5 by 0.3
1.5+2y=20
Subtract 1.5 from both sides
2y=18.5
Divide 2 on both sides
Final Answer: y= 9.25
I attached your answer below...
First make x the subject:-
3x = F(x) + 4
x = (F(x) + 4) / 3
f(-1(x) = (x + 4) / 3 answer
i am sorry i was gonna anwer but i keep getting it wrong mys elf